Seems like the answer may be to get the ModWright guys (Dan Wright) (www.modwright.com) to offer a modded Integra. Start with the stock unit. Keep the codecs and connectivity, keep the DSP, keep the Audyssey, clean up some of the shielding, and at the final stage replace the Burr-Brown DAC with something truly sweet and high-end.
or -
Keep the Integra DSP and do HDMI-out into an external multi-channel DAC that takes HDMI 1.3! (does that even exist?). Let the new pre-pros do their thing (digital compatiblity, decoding, EQ'ing). Then let audiophile-quality DACs do their thing to the final digitial signal.